CompTIA Security Plus: Ports, Protocols and Attacks Flashcards

Question 1

Define FTP (Ports 20 and 21).

Accepted Answer

File Transfer Protocol uses TCP port 21 for commands and port 20 for active-mode data, and it sends logins and files across the network without encryption.

Question 2

Define SSH (Port 22).

Accepted Answer

Secure Shell runs on TCP port 22 and provides an encrypted remote command line, which also carries secure file transfer through SFTP and SCP.

Question 3

Define Telnet (Port 23).

Accepted Answer

Telnet is a legacy remote command-line protocol on TCP port 23 that sends every keystroke unencrypted, including usernames and passwords, so SSH has replaced it.

Question 4

Define SMTP (Port 25).

Accepted Answer

Simple Mail Transfer Protocol moves email between mail servers on TCP port 25, while encrypted client submission commonly uses port 587 or port 465.

Question 5

Define DNS (Port 53).

Accepted Answer

Domain Name System translates names into IP addresses on port 53, using UDP for most lookups and TCP for zone transfers and larger responses.

Question 6

Define DHCP (Ports 67 and 68).

Accepted Answer

Dynamic Host Configuration Protocol automatically hands out IP settings to devices, with servers listening on UDP port 67 and clients receiving on UDP port 68.

Question 7

Define TFTP (Port 69).

Accepted Answer

Trivial File Transfer Protocol is a minimal file transfer service on UDP port 69 with no authentication or encryption, often used to boot or configure network devices.

Question 8

Define HTTP (Port 80).

Accepted Answer

Hypertext Transfer Protocol carries web traffic on TCP port 80 without encryption, so anyone able to observe the connection can read or change its contents.

Question 9

Define POP3 (Port 110).

Accepted Answer

Post Office Protocol version 3 lets a mail client download messages on TCP port 110, typically storing them locally, and it provides no encryption by itself.

Question 10

Define NTP (Port 123).

Accepted Answer

Network Time Protocol keeps device clocks synchronized over UDP port 123, which makes log timelines reliable and supports time-sensitive authentication such as Kerberos.

Question 11

Define IMAP (Port 143).

Accepted Answer

Internet Message Access Protocol lets mail clients read messages kept on the server over TCP port 143, keeping folders consistent across devices, and it is not encrypted by default.

Question 12

Define SNMP (Ports 161 and 162).

Accepted Answer

Simple Network Management Protocol monitors network devices, with queries on UDP port 161 and alerts called traps on UDP port 162; version 3 adds authentication and encryption.

Question 13

Define Syslog (Port 514).

Accepted Answer

Syslog is the standard format for sending log messages to a central collector, traditionally over UDP port 514, with TLS-protected transport commonly using TCP port 6514.

Question 14

Define LDAP (Port 389).

Accepted Answer

Lightweight Directory Access Protocol queries and updates directory services such as user and group records on port 389, and it is unencrypted unless protected by TLS.

Question 15

Define HTTPS (Port 443).

Accepted Answer

Hypertext Transfer Protocol Secure is web traffic carried inside a TLS session on TCP port 443, protecting its confidentiality and integrity and authenticating the server by certificate.

Question 16

Define SMB (Port 445).

Accepted Answer

Server Message Block provides Windows file and printer sharing over TCP port 445, and it should never be exposed to the internet because worms have repeatedly abused it.

Question 17

Define LDAPS (Port 636).

Accepted Answer

LDAP over TLS encrypts directory lookups and logins on port 636, which stops credentials and records being read as they cross the network.

Question 18

Define IMAPS (Port 993).

Accepted Answer

IMAP over TLS is the encrypted version of server-side mailbox access, using TCP port 993 so that messages and login details stay protected in transit.

Question 19

Define POP3S (Port 995).

Accepted Answer

POP3 over TLS is the encrypted version of download-style mail retrieval, using TCP port 995 in place of the cleartext service on port 110.

Question 20

Define RDP (Port 3389).

Accepted Answer

Remote Desktop Protocol gives graphical control of a Windows machine over port 3389, and exposing it directly to the internet makes it a frequent target for credential attacks.

Question 21

Define On-Path Attack.

Accepted Answer

An attack in which the adversary secretly positions themselves between two communicating systems, allowing them to observe, relay or alter traffic while each side believes it has a direct connection.

Question 22

Define Replay Attack.

Accepted Answer

An attack that captures valid data, such as an authentication message or session token, and sends the same data again later to impersonate the original user.

Question 23

Define Protocol Downgrade Attack.

Accepted Answer

An attack that manipulates the negotiation between two systems so they use an older or weaker protocol version or cipher, whose known flaws are easier to exploit.

Question 24

Define DNS Cache Poisoning.

Accepted Answer

Inserting a false record into a resolver's cache, so that users asking for a legitimate domain name receive an attacker-controlled IP address until the record expires.

Question 25

What is Sniffing?

Accepted Answer

Capturing network traffic with a tool called a packet analyzer in order to read its contents, which is a passive activity that does not alter the data.

Question 26

What is Spoofing?

Accepted Answer

Forging an identifying detail, such as an IP address, MAC address or email sender, so that a message or device appears to come from a trusted source.

Question 27

Define Distributed Denial of Service (DDoS).

Accepted Answer

An attack that uses many systems at once to overwhelm a target's bandwidth or resources, so that legitimate users can no longer reach the service.

Question 28

Define Password Spraying.

Accepted Answer

A credential attack that tries a small number of common passwords across many accounts, keeping attempts per account low enough to avoid triggering account lockouts.

Question 29

Define Brute Force Attack.

Accepted Answer

A credential attack that systematically tries a very large number of possible passwords against an account or a stolen hash until one of them works.

Question 30

Define User Enumeration.

Accepted Answer

Discovering which usernames are valid by observing how a system responds differently to real and fake accounts, producing a target list for later password attacks.

Question 31

Define MFA Bypass.

Accepted Answer

Any technique that gets past multifactor authentication without defeating the factor itself, for example by tricking the user, stealing a session token or abusing a weak recovery process.

Question 32

Define Injection Attack.

Accepted Answer

An application attack in which untrusted input is interpreted as a command or query, causing a database or other interpreter to do something the developer never intended.

Question 33

Define Directory Traversal.

Accepted Answer

An application attack that manipulates a file path, usually with dot-dot-slash sequences, to reach files and folders outside the location the application is meant to serve.

Question 34

Define Rogue Access Point.

Accepted Answer

A wireless access point connected or operating without authorization, which can create an unmonitored way into a network or trick users into sending traffic through an attacker.